<?php
/*
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

namespace Doctrine\DBAL;

use PDO, Closure, Exception, Doctrine\DBAL\Types\Type, Doctrine\DBAL\Driver\Connection as DriverConnection, Doctrine\Common\EventManager, Doctrine\DBAL\DBALException;

/**
 * A wrapper around a Doctrine\DBAL\Driver\Connection that adds features like
 * events, transaction isolation levels, configuration, emulated transaction nesting,
 * lazy connecting and more.
 *
 * @license http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link    www.doctrine-project.org
 * @since   2.0
 * @version $Revision: 3938 $
 * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
 * @author  Jonathan Wage <jonwage@gmail.com>
 * @author  Roman Borschel <roman@code-factory.org>
 * @author  Konsta Vesterinen <kvesteri@cc.hut.fi>
 * @author  Lukas Smith <smith@pooteeweet.org> (MDB2 library)
 * @author  Benjamin Eberlei <kontakt@beberlei.de>
 */
class Connection implements DriverConnection {
	/**
	 * Constant for transaction isolation level READ UNCOMMITTED.
	 */
	const TRANSACTION_READ_UNCOMMITTED = 1;
	
	/**
	 * Constant for transaction isolation level READ COMMITTED.
	 */
	const TRANSACTION_READ_COMMITTED = 2;
	
	/**
	 * Constant for transaction isolation level REPEATABLE READ.
	 */
	const TRANSACTION_REPEATABLE_READ = 3;
	
	/**
	 * Constant for transaction isolation level SERIALIZABLE.
	 */
	const TRANSACTION_SERIALIZABLE = 4;
	
	/**
	 * The wrapped driver connection.
	 *
	 * @var Doctrine\DBAL\Driver\Connection
	 */
	protected $_conn;
	
	/**
	 * @var Doctrine\DBAL\Configuration
	 */
	protected $_config;
	
	/**
	 * @var Doctrine\Common\EventManager
	 */
	protected $_eventManager;
	
	/**
	 * Whether or not a connection has been established.
	 *
	 * @var boolean
	 */
	private $_isConnected = false;
	
	/**
	 * The transaction nesting level.
	 *
	 * @var integer
	 */
	private $_transactionNestingLevel = 0;
	
	/**
	 * The currently active transaction isolation level.
	 *
	 * @var integer
	 */
	private $_transactionIsolationLevel;
	
	/**
	 * If nested transations should use savepoints
	 *
	 * @var integer
	 */
	private $_nestTransactionsWithSavepoints;
	
	/**
	 * The parameters used during creation of the Connection instance.
	 *
	 * @var array
	 */
	private $_params = array();
	
	/**
	 * The DatabasePlatform object that provides information about the
	 * database platform used by the connection.
	 *
	 * @var Doctrine\DBAL\Platforms\AbstractPlatform
	 */
	protected $_platform;
	
	/**
	 * The schema manager.
	 *
	 * @var Doctrine\DBAL\Schema\SchemaManager
	 */
	protected $_schemaManager;
	
	/**
	 * The used DBAL driver.
	 *
	 * @var Doctrine\DBAL\Driver
	 */
	protected $_driver;
	
	/**
	 * Flag that indicates whether the current transaction is marked for rollback only.
	 * 
	 * @var boolean
	 */
	private $_isRollbackOnly = false;
	
	/**
	 * Initializes a new instance of the Connection class.
	 *
	 * @param array $params  The connection parameters.
	 * @param Driver $driver
	 * @param Configuration $config
	 * @param EventManager $eventManager
	 */
	public function __construct(array $params, Driver $driver, Configuration $config = null, EventManager $eventManager = null) {
		$this->_driver = $driver;
		$this->_params = $params;
		
		if( isset( $params['pdo'] ) ) {
			$this->_conn = $params['pdo'];
			$this->_isConnected = true;
		}
		
		// Create default config and event manager if none given
		if( !$config ) {
			$config = new Configuration();
		}
		
		if( !$eventManager ) {
			$eventManager = new EventManager();
		}
		
		$this->_config = $config;
		$this->_eventManager = $eventManager;
		if( !isset( $params['platform'] ) ) {
			$this->_platform = $driver->getDatabasePlatform();
		} else if( $params['platform'] instanceof Platforms\AbstractPlatform ) {
			$this->_platform = $params['platform'];
		} else {
			throw DBALException::invalidPlatformSpecified();
		}
		$this->_transactionIsolationLevel = $this->_platform->getDefaultTransactionIsolationLevel();
	}
	
	/**
	 * Gets the parameters used during instantiation.
	 *
	 * @return array $params
	 */
	public function getParams() {
		return $this->_params;
	}
	
	/**
	 * Gets the name of the database this Connection is connected to.
	 *
	 * @return string $database
	 */
	public function getDatabase() {
		return $this->_driver->getDatabase( $this );
	}
	
	/**
	 * Gets the hostname of the currently connected database.
	 * 
	 * @return string
	 */
	public function getHost() {
		return isset( $this->_params['host'] ) ? $this->_params['host'] : null;
	}
	
	/**
	 * Gets the port of the currently connected database.
	 * 
	 * @return mixed
	 */
	public function getPort() {
		return isset( $this->_params['port'] ) ? $this->_params['port'] : null;
	}
	
	/**
	 * Gets the username used by this connection.
	 * 
	 * @return string
	 */
	public function getUsername() {
		return isset( $this->_params['user'] ) ? $this->_params['user'] : null;
	}
	
	/**
	 * Gets the password used by this connection.
	 * 
	 * @return string
	 */
	public function getPassword() {
		return isset( $this->_params['password'] ) ? $this->_params['password'] : null;
	}
	
	/**
	 * Gets the DBAL driver instance.
	 *
	 * @return Doctrine\DBAL\Driver
	 */
	public function getDriver() {
		return $this->_driver;
	}
	
	/**
	 * Gets the Configuration used by the Connection.
	 *
	 * @return Doctrine\DBAL\Configuration
	 */
	public function getConfiguration() {
		return $this->_config;
	}
	
	/**
	 * Gets the EventManager used by the Connection.
	 *
	 * @return Doctrine\Common\EventManager
	 */
	public function getEventManager() {
		return $this->_eventManager;
	}
	
	/**
	 * Gets the DatabasePlatform for the connection.
	 *
	 * @return Doctrine\DBAL\Platforms\AbstractPlatform
	 */
	public function getDatabasePlatform() {
		return $this->_platform;
	}
	
	/**
	 * Establishes the connection with the database.
	 *
	 * @return boolean TRUE if the connection was successfully established, FALSE if
	 * the connection is already open.
	 */
	public function connect() {
		if( $this->_isConnected )
			return false;
		
		$driverOptions = isset( $this->_params['driverOptions'] ) ? $this->_params['driverOptions'] : array();
		$user = isset( $this->_params['user'] ) ? $this->_params['user'] : null;
		$password = isset( $this->_params['password'] ) ? $this->_params['password'] : null;
		
		$this->_conn = $this->_driver->connect( $this->_params, $user, $password, $driverOptions );
		$this->_isConnected = true;
		
		if( $this->_eventManager->hasListeners( Events::postConnect ) ) {
			$eventArgs = new Event\ConnectionEventArgs( $this );
			$this->_eventManager->dispatchEvent( Events::postConnect, $eventArgs );
		}
		
		return true;
	}
	
	/**
	 * Prepares and executes an SQL query and returns the first row of the result
	 * as an associative array.
	 * 
	 * @param string $statement The SQL query.
	 * @param array $params The query parameters.
	 * @return array
	 */
	public function fetchAssoc($statement, array $params = array()) {
		return $this->executeQuery( $statement, $params )->fetch( PDO::FETCH_ASSOC );
	}
	
	/**
	 * Prepares and executes an SQL query and returns the first row of the result
	 * as a numerically indexed array.
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @return array
	 */
	public function fetchArray($statement, array $params = array()) {
		return $this->executeQuery( $statement, $params )->fetch( PDO::FETCH_NUM );
	}
	
	/**
	 * Prepares and executes an SQL query and returns the value of a single column
	 * of the first row of the result.
	 * 
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @param int $colnum               0-indexed column number to retrieve
	 * @return mixed
	 */
	public function fetchColumn($statement, array $params = array(), $colnum = 0) {
		return $this->executeQuery( $statement, $params )->fetchColumn( $colnum );
	}
	
	/**
	 * Whether an actual connection to the database is established.
	 *
	 * @return boolean
	 */
	public function isConnected() {
		return $this->_isConnected;
	}
	
	/**
	 * Checks whether a transaction is currently active.
	 * 
	 * @return boolean TRUE if a transaction is currently active, FALSE otherwise.
	 */
	public function isTransactionActive() {
		return $this->_transactionNestingLevel > 0;
	}
	
	/**
	 * Executes an SQL DELETE statement on a table.
	 *
	 * @param string $table The name of the table on which to delete.
	 * @param array $identifier The deletion criteria. An associateve array containing column-value pairs.
	 * @return integer The number of affected rows.
	 */
	public function delete($tableName, array $identifier) {
		$this->connect();
		
		$criteria = array();
		
		foreach( array_keys( $identifier ) as $columnName ) {
			$criteria[] = $columnName . ' = ?';
		}
		
		$query = 'DELETE FROM ' . $tableName . ' WHERE ' . implode( ' AND ', $criteria );
		
		return $this->executeUpdate( $query, array_values( $identifier ) );
	}
	
	/**
	 * Closes the connection.
	 *
	 * @return void
	 */
	public function close() {
		unset( $this->_conn );
		
		$this->_isConnected = false;
	}
	
	/**
	 * Sets the transaction isolation level.
	 *
	 * @param integer $level The level to set.
	 */
	public function setTransactionIsolation($level) {
		$this->_transactionIsolationLevel = $level;
		
		return $this->executeUpdate( $this->_platform->getSetTransactionIsolationSQL( $level ) );
	}
	
	/**
	 * Gets the currently active transaction isolation level.
	 *
	 * @return integer The current transaction isolation level.
	 */
	public function getTransactionIsolation() {
		return $this->_transactionIsolationLevel;
	}
	
	/**
	 * Executes an SQL UPDATE statement on a table.
	 *
	 * @param string $table The name of the table to update.
	 * @param array $identifier The update criteria. An associative array containing column-value pairs.
	 * @return integer The number of affected rows.
	 */
	public function update($tableName, array $data, array $identifier) {
		$this->connect();
		$set = array();
		foreach( $data as $columnName => $value ) {
			$set[] = $columnName . ' = ?';
		}
		
		$params = array_merge( array_values( $data ), array_values( $identifier ) );
		
		$sql = 'UPDATE ' . $tableName . ' SET ' . implode( ', ', $set ) . ' WHERE ' . implode( ' = ? AND ', array_keys( $identifier ) ) . ' = ?';
		
		return $this->executeUpdate( $sql, $params );
	}
	
	/**
	 * Inserts a table row with specified data.
	 *
	 * @param string $table The name of the table to insert data into.
	 * @param array $data An associative array containing column-value pairs.
	 * @return integer The number of affected rows.
	 */
	public function insert($tableName, array $data) {
		$this->connect();
		
		// column names are specified as array keys
		$cols = array();
		$placeholders = array();
		
		foreach( $data as $columnName => $value ) {
			$cols[] = $columnName;
			$placeholders[] = '?';
		}
		
		$query = 'INSERT INTO ' . $tableName . ' (' . implode( ', ', $cols ) . ')' . ' VALUES (' . implode( ', ', $placeholders ) . ')';
		
		return $this->executeUpdate( $query, array_values( $data ) );
	}
	
	/**
	 * Sets the given charset on the current connection.
	 *
	 * @param string $charset The charset to set.
	 */
	public function setCharset($charset) {
		$this->executeUpdate( $this->_platform->getSetCharsetSQL( $charset ) );
	}
	
	/**
	 * Quote a string so it can be safely used as a table or column name, even if
	 * it is a reserved name.
	 *
	 * Delimiting style depends on the underlying database platform that is being used.
	 *
	 * NOTE: Just because you CAN use quoted identifiers does not mean
	 * you SHOULD use them. In general, they end up causing way more
	 * problems than they solve.
	 *
	 * @param string $str The name to be quoted.
	 * @return string The quoted name.
	 */
	public function quoteIdentifier($str) {
		return $this->_platform->quoteIdentifier( $str );
	}
	
	/**
	 * Quotes a given input parameter.
	 *
	 * @param mixed $input Parameter to be quoted.
	 * @param string $type Type of the parameter.
	 * @return string The quoted parameter.
	 */
	public function quote($input, $type = null) {
		$this->connect();
		
		return $this->_conn->quote( $input, $type );
	}
	
	/**
	 * Prepares and executes an SQL query and returns the result as an associative array.
	 *
	 * @param string $sql The SQL query.
	 * @param array $params The query parameters.
	 * @return array
	 */
	public function fetchAll($sql, array $params = array()) {
		return $this->executeQuery( $sql, $params )->fetchAll( PDO::FETCH_ASSOC );
	}
	
	/**
	 * Prepares an SQL statement.
	 *
	 * @param string $statement The SQL statement to prepare.
	 * @return Doctrine\DBAL\Driver\Statement The prepared statement.
	 */
	public function prepare($statement) {
		$this->connect();
		
		return new Statement( $statement, $this );
	}
	
	/**
	 * Executes an, optionally parameterized, SQL query.
	 *
	 * If the query is parameterized, a prepared statement is used.
	 * If an SQLLogger is configured, the execution is logged.
	 *
	 * @param string $query The SQL query to execute.
	 * @param array $params The parameters to bind to the query, if any.
	 * @return Doctrine\DBAL\Driver\Statement The executed statement.
	 * @internal PERF: Directly prepares a driver statement, not a wrapper.
	 */
	public function executeQuery($query, array $params = array(), $types = array()) {
		$this->connect();
		
		$hasLogger = $this->_config->getSQLLogger() !== null;
		if( $hasLogger ) {
			$this->_config->getSQLLogger()->startQuery( $query, $params, $types );
		}
		
		if( $params ) {
			$stmt = $this->_conn->prepare( $query );
			if( $types ) {
				$this->_bindTypedValues( $stmt, $params, $types );
				$stmt->execute();
			} else {
				$stmt->execute( $params );
			}
		} else {
			$stmt = $this->_conn->query( $query );
		}
		
		if( $hasLogger ) {
			$this->_config->getSQLLogger()->stopQuery();
		}
		
		return $stmt;
	}
	
	/**
	 * Executes an, optionally parameterized, SQL query and returns the result,
	 * applying a given projection/transformation function on each row of the result.
	 *
	 * @param string $query The SQL query to execute.
	 * @param array $params The parameters, if any.
	 * @param Closure $mapper The transformation function that is applied on each row.
	 * The function receives a single paramater, an array, that
	 * represents a row of the result set.
	 * @return mixed The projected result of the query.
	 */
	public function project($query, array $params, Closure $function) {
		$result = array();
		$stmt = $this->executeQuery( $query, $params ?  : array() );
		
		while ( $row = $stmt->fetch() ) {
			$result[] = $function( $row );
		}
		
		$stmt->closeCursor();
		
		return $result;
	}
	
	/**
	 * Executes an SQL statement, returning a result set as a Statement object.
	 * 
	 * @param string $statement
	 * @param integer $fetchType
	 * @return Doctrine\DBAL\Driver\Statement
	 */
	public function query() {
		$this->connect();
		
		return call_user_func_array( array( $this->_conn, 'query' ), func_get_args() );
	}
	
	/**
	 * Executes an SQL INSERT/UPDATE/DELETE query with the given parameters
	 * and returns the number of affected rows.
	 * 
	 * This method supports PDO binding types as well as DBAL mapping types.
	 *
	 * @param string $query The SQL query.
	 * @param array $params The query parameters.
	 * @param array $types The parameter types.
	 * @return integer The number of affected rows.
	 * @internal PERF: Directly prepares a driver statement, not a wrapper.
	 */
	public function executeUpdate($query, array $params = array(), array $types = array()) {
		$this->connect();
		
		$hasLogger = $this->_config->getSQLLogger() !== null;
		if( $hasLogger ) {
			$this->_config->getSQLLogger()->startQuery( $query, $params, $types );
		}
		
		if( $params ) {
			$stmt = $this->_conn->prepare( $query );
			if( $types ) {
				$this->_bindTypedValues( $stmt, $params, $types );
				$stmt->execute();
			} else {
				$stmt->execute( $params );
			}
			$result = $stmt->rowCount();
		} else {
			$result = $this->_conn->exec( $query );
		}
		
		if( $hasLogger ) {
			$this->_config->getSQLLogger()->stopQuery();
		}
		
		return $result;
	}
	
	/**
	 * Execute an SQL statement and return the number of affected rows.
	 * 
	 * @param string $statement
	 * @return integer The number of affected rows.
	 */
	public function exec($statement) {
		$this->connect();
		return $this->_conn->exec( $statement );
	}
	
	/**
	 * Returns the current transaction nesting level.
	 *
	 * @return integer The nesting level. A value of 0 means there's no active transaction.
	 */
	public function getTransactionNestingLevel() {
		return $this->_transactionNestingLevel;
	}
	
	/**
	 * Fetch the SQLSTATE associated with the last database operation.
	 *
	 * @return integer The last error code.
	 */
	public function errorCode() {
		$this->connect();
		return $this->_conn->errorCode();
	}
	
	/**
	 * Fetch extended error information associated with the last database operation.
	 *
	 * @return array The last error information.
	 */
	public function errorInfo() {
		$this->connect();
		return $this->_conn->errorInfo();
	}
	
	/**
	 * Returns the ID of the last inserted row, or the last value from a sequence object,
	 * depending on the underlying driver.
	 *
	 * Note: This method may not return a meaningful or consistent result across different drivers,
	 * because the underlying database may not even support the notion of AUTO_INCREMENT/IDENTITY
	 * columns or sequences.
	 *
	 * @param string $seqName Name of the sequence object from which the ID should be returned.
	 * @return string A string representation of the last inserted ID.
	 */
	public function lastInsertId($seqName = null) {
		$this->connect();
		return $this->_conn->lastInsertId( $seqName );
	}
	
	/**
	 * Executes a function in a transaction.
	 *
	 * The function gets passed this Connection instance as an (optional) parameter.
	 *
	 * If an exception occurs during execution of the function or transaction commit,
	 * the transaction is rolled back and the exception re-thrown.
	 *
	 * @param Closure $func The function to execute transactionally.
	 */
	public function transactional(Closure $func) {
		$this->beginTransaction();
		try {
			$func( $this );
			$this->commit();
		} catch ( Exception $e ) {
			$this->rollback();
			throw $e;
		}
	}
	
	/**
	 * Set if nested transactions should use savepoints
	 *
	 * @param boolean
	 * @return void
	 */
	public function setNestTransactionsWithSavepoints($nestTransactionsWithSavepoints) {
		if( $this->_transactionNestingLevel > 0 ) {
			throw ConnectionException::mayNotAlterNestedTransactionWithSavepointsInTransaction();
		}
		
		if( !$this->_platform->supportsSavepoints() ) {
			throw ConnectionException::savepointsNotSupported();
		}
		
		$this->_nestTransactionsWithSavepoints = $nestTransactionsWithSavepoints;
	}
	
	/**
	 * Get if nested transactions should use savepoints
	 *
	 * @return boolean
	 */
	public function getNestTransactionsWithSavepoints() {
		return $this->_nestTransactionsWithSavepoints;
	}
	
	/**
	 * Returns the savepoint name to use for nested transactions are false if they are not supported
	 * "savepointFormat" parameter is not set
	 *
	 * @return mixed a string with the savepoint name or false
	 */
	protected function _getNestedTransactionSavePointName() {
		return 'DOCTRINE2_SAVEPOINT_' . $this->_transactionNestingLevel;
	}
	
	/**
	 * Starts a transaction by suspending auto-commit mode.
	 *
	 * @return void
	 */
	public function beginTransaction() {
		$this->connect();
		
		++$this->_transactionNestingLevel;
		
		if( $this->_transactionNestingLevel == 1 ) {
			$this->_conn->beginTransaction();
		} else if( $this->_nestTransactionsWithSavepoints ) {
			$this->createSavepoint( $this->_getNestedTransactionSavePointName() );
		}
	}
	
	/**
	 * Commits the current transaction.
	 *
	 * @return void
	 * @throws ConnectionException If the commit failed due to no active transaction or
	 * because the transaction was marked for rollback only.
	 */
	public function commit() {
		if( $this->_transactionNestingLevel == 0 ) {
			throw ConnectionException::noActiveTransaction();
		}
		if( $this->_isRollbackOnly ) {
			throw ConnectionException::commitFailedRollbackOnly();
		}
		
		$this->connect();
		
		if( $this->_transactionNestingLevel == 1 ) {
			$this->_conn->commit();
		} else if( $this->_nestTransactionsWithSavepoints ) {
			$this->releaseSavepoint( $this->_getNestedTransactionSavePointName() );
		}
		
		--$this->_transactionNestingLevel;
	}
	
	/**
	 * Cancel any database changes done during the current transaction.
	 *
	 * this method can be listened with onPreTransactionRollback and onTransactionRollback
	 * eventlistener methods
	 *
	 * @throws ConnectionException If the rollback operation failed.
	 */
	public function rollback() {
		if( $this->_transactionNestingLevel == 0 ) {
			throw ConnectionException::noActiveTransaction();
		}
		
		$this->connect();
		
		if( $this->_transactionNestingLevel == 1 ) {
			$this->_transactionNestingLevel = 0;
			$this->_conn->rollback();
			$this->_isRollbackOnly = false;
		} else if( $this->_nestTransactionsWithSavepoints ) {
			$this->rollbackSavepoint( $this->_getNestedTransactionSavePointName() );
			--$this->_transactionNestingLevel;
		} else {
			$this->_isRollbackOnly = true;
			--$this->_transactionNestingLevel;
		}
	}
	
	/**
	 * createSavepoint
	 * creates a new savepoint
	 *
	 * @param string $savepoint     name of a savepoint to set
	 * @return void
	 */
	public function createSavepoint($savepoint) {
		if( !$this->_platform->supportsSavepoints() ) {
			throw ConnectionException::savepointsNotSupported();
		}
		
		$this->_conn->exec( $this->_platform->createSavePoint( $savepoint ) );
	}
	
	/**
	 * releaseSavePoint
	 * releases given savepoint
	 *
	 * @param string $savepoint     name of a savepoint to release
	 * @return void
	 */
	public function releaseSavepoint($savepoint) {
		if( !$this->_platform->supportsSavepoints() ) {
			throw ConnectionException::savepointsNotSupported();
		}
		
		if( $this->_platform->supportsReleaseSavepoints() ) {
			$this->_conn->exec( $this->_platform->releaseSavePoint( $savepoint ) );
		}
	}
	
	/**
	 * rollbackSavePoint
	 * releases given savepoint
	 *
	 * @param string $savepoint     name of a savepoint to rollback to
	 * @return void
	 */
	public function rollbackSavepoint($savepoint) {
		if( !$this->_platform->supportsSavepoints() ) {
			throw ConnectionException::savepointsNotSupported();
		}
		
		$this->_conn->exec( $this->_platform->rollbackSavePoint( $savepoint ) );
	}
	
	/**
	 * Gets the wrapped driver connection.
	 *
	 * @return Doctrine\DBAL\Driver\Connection
	 */
	public function getWrappedConnection() {
		$this->connect();
		
		return $this->_conn;
	}
	
	/**
	 * Gets the SchemaManager that can be used to inspect or change the
	 * database schema through the connection.
	 *
	 * @return Doctrine\DBAL\Schema\SchemaManager
	 */
	public function getSchemaManager() {
		if( !$this->_schemaManager ) {
			$this->_schemaManager = $this->_driver->getSchemaManager( $this );
		}
		
		return $this->_schemaManager;
	}
	
	/**
	 * Marks the current transaction so that the only possible
	 * outcome for the transaction to be rolled back.
	 * 
	 * @throws ConnectionException If no transaction is active.
	 */
	public function setRollbackOnly() {
		if( $this->_transactionNestingLevel == 0 ) {
			throw ConnectionException::noActiveTransaction();
		}
		$this->_isRollbackOnly = true;
	}
	
	/**
	 * Check whether the current transaction is marked for rollback only.
	 * 
	 * @return boolean
	 * @throws ConnectionException If no transaction is active.
	 */
	public function isRollbackOnly() {
		if( $this->_transactionNestingLevel == 0 ) {
			throw ConnectionException::noActiveTransaction();
		}
		return $this->_isRollbackOnly;
	}
	
	/**
	 * Converts a given value to its database representation according to the conversion
	 * rules of a specific DBAL mapping type.
	 * 
	 * @param mixed $value The value to convert.
	 * @param string $type The name of the DBAL mapping type.
	 * @return mixed The converted value.
	 */
	public function convertToDatabaseValue($value, $type) {
		return Type::getType( $type )->convertToDatabaseValue( $value, $this->_platform );
	}
	
	/**
	 * Converts a given value to its PHP representation according to the conversion
	 * rules of a specific DBAL mapping type.
	 * 
	 * @param mixed $value The value to convert.
	 * @param string $type The name of the DBAL mapping type.
	 * @return mixed The converted type.
	 */
	public function convertToPHPValue($value, $type) {
		return Type::getType( $type )->convertToPHPValue( $value, $this->_platform );
	}
	
	/**
	 * Binds a set of parameters, some or all of which are typed with a PDO binding type
	 * or DBAL mapping type, to a given statement.
	 * 
	 * @param $stmt The statement to bind the values to.
	 * @param array $params The map/list of named/positional parameters.
	 * @param array $types The parameter types (PDO binding types or DBAL mapping types).
	 * @internal Duck-typing used on the $stmt parameter to support driver statements as well as
	 * raw PDOStatement instances.
	 */
	private function _bindTypedValues($stmt, array $params, array $types) {
		// Check whether parameters are positional or named. Mixing is not allowed, just like in PDO.
		if( is_int( key( $params ) ) ) {
			// Positional parameters
			$typeOffset = array_key_exists( 0, $types ) ? -1 : 0;
			$bindIndex = 1;
			foreach( $params as $position => $value ) {
				$typeIndex = $bindIndex + $typeOffset;
				if( isset( $types[$typeIndex] ) ) {
					$type = $types[$typeIndex];
					if( is_string( $type ) ) {
						$type = Type::getType( $type );
					}
					if( $type instanceof Type ) {
						$value = $type->convertToDatabaseValue( $value, $this->_platform );
						$bindingType = $type->getBindingType();
					} else {
						$bindingType = $type; // PDO::PARAM_* constants
					}
					$stmt->bindValue( $bindIndex, $value, $bindingType );
				} else {
					$stmt->bindValue( $bindIndex, $value );
				}
				++$bindIndex;
			}
		} else {
			// Named parameters
			foreach( $params as $name => $value ) {
				if( isset( $types[$name] ) ) {
					$type = $types[$name];
					if( is_string( $type ) ) {
						$type = Type::getType( $type );
					}
					if( $type instanceof Type ) {
						$value = $type->convertToDatabaseValue( $value, $this->_platform );
						$bindingType = $type->getBindingType();
					} else {
						$bindingType = $type; // PDO::PARAM_* constants
					}
					$stmt->bindValue( $name, $value, $bindingType );
				} else {
					$stmt->bindValue( $name, $value );
				}
			}
		}
	}
}